/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.explorer.ui.management.processinstance;

import com.vaadin.data.Item;
import org.activiti.engine.ProcessEngines;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.RuntimeService;
import org.activiti.engine.repository.ProcessDefinition;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.runtime.ProcessInstanceQuery;
import org.activiti.explorer.data.AbstractLazyLoadingQuery;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * @author Joram Barrez
 */
public class ProcessInstanceListQuery extends AbstractLazyLoadingQuery {

    protected transient RuntimeService runtimeService;
    protected transient RepositoryService repositoryService;

    protected Map<String, String> cachedProcessDefinitionNames = new HashMap<String, String>();

    public ProcessInstanceListQuery() {
        this.runtimeService = ProcessEngines.getDefaultProcessEngine().getRuntimeService();
        this.repositoryService = ProcessEngines.getDefaultProcessEngine().getRepositoryService();
    }

    public int size() {
        return (int) constructQuery().count();
    }

    public List<Item> loadItems(int start, int count) {
        List<ProcessInstance> processInstances = constructQuery().listPage(start, count);
        List<Item> items = new ArrayList<Item>();
        for (ProcessInstance processInstance : processInstances) {
            items.add(new ProcessInstanceListItem(processInstance, getProcessDefinitionName(processInstance.getProcessDefinitionId())));
        }
        return items;
    }

    public Item loadSingleResult(String id) {
        ProcessInstance processInstance = constructQuery().processInstanceId(id).singleResult();
        return new ProcessInstanceListItem(processInstance, processInstance.getProcessDefinitionId());
    }

    public void setSorting(Object[] propertyIds, boolean[] ascending) {
        throw new UnsupportedOperationException();
    }

    protected ProcessInstanceQuery constructQuery() {
        return runtimeService.createProcessInstanceQuery()
                .orderByProcessInstanceId().asc();
    }

    protected String getProcessDefinitionName(String processDefinitionId) {
        if (!cachedProcessDefinitionNames.containsKey(processDefinitionId)) {
            ProcessDefinition definition = repositoryService.createProcessDefinitionQuery()
                    .processDefinitionId(processDefinitionId).singleResult();

            String name = definition.getName();
            if (name != null) {
                name = definition.getKey();
            }
            cachedProcessDefinitionNames.put(processDefinitionId, name);
        }
        return cachedProcessDefinitionNames.get(processDefinitionId);
    }

}
